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DSST Lifespan Developmental Psychology study materials
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DSST Lifespan Developmental Psychology practice questions

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Question 1Ethical issues

A researcher wants to study how infants respond to a new mobile app designed to teach colors. Before beginning, the researcher must obtain approval from which body to ensure participant welfare is protected?

  1. The funding agency's marketing department
  2. The journal that will publish the study
  3. The Institutional Review Board (IRB) Correct answer.
  4. The app's software development company

Explanation

Institutional Review Boards review research involving human participants to ensure that risks are minimized and that informed consent and confidentiality protections are in place. Approval must precede data collection, not follow publication or depend on commercial sponsors.

Question 2Ethical issues

In a longitudinal study of adolescent identity, a 15-year-old participant is asked to complete surveys about family conflict. Which consent procedure is ethically required?

  1. Parental permission plus the adolescent's assent Correct answer.
  2. Verbal consent from a teacher who knows the family
  3. Only the parents' written consent
  4. Only the adolescent's own written consent

Explanation

Minors cannot legally give consent, so researchers obtain permission from parents or guardians and, when developmentally appropriate, the child's assent. Obtaining both respects the adolescent's emerging autonomy while satisfying legal protections.

Question 3Ethical issues

A developmental psychologist studying attachment observes that a mother appears distressed during a laboratory procedure. What is the researcher's primary ethical obligation?

  1. Record the distress as a valuable dependent variable
  2. Ask the mother to sign a new consent form before continuing
  3. Continue the procedure because the protocol was already approved
  4. Stop and address the participant's distress, even if it disrupts data collection Correct answer.

Explanation

Researchers must protect participants from harm, and distress is a signal to pause or intervene rather than a data point to exploit. Prior IRB approval does not override the obligation to respond to foreseeable or emerging harm.

Question 4Ethical issues

Researchers analyzing archival data from a school district's records find that individual student names are included. To protect participants, the team should do which of the following before analysis?

  1. Share the raw file with all co-authors by email
  2. Remove or replace identifying information with codes Correct answer.
  3. Post the dataset on a public website for replication
  4. Publish the names to ensure transparency

Explanation

Confidentiality requires that identifiable data be de-identified or coded so that individuals cannot be linked to their responses. Public exposure or unrestricted sharing of names would violate participants' privacy expectations.

Question 5Ethical issues

Which principle from the Belmont Report refers to treating people as autonomous agents and protecting those with diminished autonomy?

  1. Respect for persons Correct answer.
  2. Beneficence
  3. Justice
  4. Integrity

Explanation

Respect for persons requires acknowledging autonomy and providing extra protection for individuals with diminished capacity, such as young children or cognitively impaired adults. Beneficence concerns maximizing benefits, justice concerns fairness of distribution, and integrity is not a Belmont principle.

Question 6Ethical issues

A study of memory in older adults offers a $500 payment to participants. Which ethical concern is most directly raised by this payment amount?

  1. Whether the payment eliminates the need for consent
  2. Whether the payment requires a new IRB protocol
  3. Whether the payment constitutes an undue inducement Correct answer.
  4. Whether the payment violates the principle of justice

Explanation

Large payments can become undue inducements that pressure vulnerable people to accept risks they would otherwise refuse. IRBs weigh payment levels against study burden and participant vulnerability.

Question 7Ethical issues

A researcher studying language development in toddlers plans to use video recording in a home. Which practice best protects privacy while preserving data quality?

  1. Allow any lab visitor to view the recordings
  2. Record only the child and inform parents that recordings will be secured and destroyed after coding Correct answer.
  3. Store recordings on a personal unencrypted laptop
  4. Record the whole home and share clips on social media

Explanation

Minimizing what is recorded and securing and eventually destroying data limits privacy intrusion while still yielding usable observations. Sharing clips publicly, storing them insecurely, or allowing unrestricted viewing all increase confidentiality risks.

Question 8Ethical issues

During a study of peer rejection in middle childhood, a child discloses being bullied and expresses thoughts of self-harm. What is the ethically appropriate researcher response?

  1. Exclude the child's data and end all contact
  2. Keep the disclosure confidential because consent promised privacy
  3. Follow the protocol's safety plan, which may include notifying a guardian or clinician Correct answer.
  4. Publish the disclosure as an illustrative case without alteration

Explanation

Informed consent cannot promise absolute confidentiality when there is risk of serious harm; researchers must follow pre-established safety and referral procedures. Protecting the child's welfare takes precedence over data collection or absolute privacy.

Question 9Ethical issues

A cross-cultural team studies parenting practices in several countries. Which approach best reflects ethical cultural competence?

  1. Collaborating with local researchers and adapting procedures to local norms and laws Correct answer.
  2. Applying the home country's standards uniformly without consultation
  3. Avoiding local input to preserve methodological consistency
  4. Treating local ethical review as unnecessary when the home IRB has approved

Explanation

Ethical cross-cultural research requires partnership with local collaborators and attention to local norms, laws, and review requirements. Imposing one country's standards or skipping local review risks harm and disrespect.

Question 10Ethical issues

A researcher reuses data collected for an earlier study to answer a new question about sibling relationships. What is the most appropriate action?

  1. Delete all consent records to protect privacy
  2. Sell the data to another institution
  3. Proceed because the data already exist
  4. Seek IRB review of the new use and confirm consent permits it Correct answer.

Explanation

Secondary use of data requires confirming that the original consent covers the new purpose or obtaining a waiver and IRB approval. Existing data are not automatically available for any new research question.

Question 11Ethical issues

In a study of infant temperament, a researcher reports group means but also includes a table with each infant's birth date and daycare center. Why is this a concern?

  1. Because means are never reportable
  2. Because birth dates are not relevant to temperament
  3. Because daycare centers cannot be studied
  4. Because combined identifiers can re-identify individual infants Correct answer.

Explanation

Even when names are removed, combinations of quasi-identifiers such as birth dates and daycare centers can allow re-identification. Ethical reporting minimizes such combinations to preserve confidentiality.

Question 12Ethical issues

A graduate student discovers that a senior colleague fabricated data in a published developmental study. According to research-integrity norms, the student should first do which of the following?

  1. Report the concern through institutional channels for research misconduct Correct answer.
  2. Ignore it to avoid conflict
  3. Reanalyze the data and publish a correction without informing anyone
  4. Confront the colleague publicly on social media

Explanation

Research-integrity standards require reporting suspected fabrication through established institutional channels so it can be investigated fairly. Public accusation or silent correction bypasses due process and may cause additional harm.

Question 13Ethical issues

A researcher studying children's moral reasoning wants to deceive participants about the true purpose of a task. Under what condition is deception most defensible?

  1. When the IRB is not informed
  2. Whenever it makes the study easier to run
  3. Only when participants are adults
  4. When it is necessary, minimal, and followed by debriefing Correct answer.

Explanation

Deception may be justified only when it is essential to the research, involves minimal risk, and is disclosed in debriefing. Convenience, participant age, or concealment from the IRB does not justify deception.

Question 14Ethical issues

A researcher plans to compare institutionalized infants with home-reared infants on cognitive measures. Which ethical safeguard is most important?

  1. Ensuring the institutionalized group receives some direct benefit or that risks are minimized Correct answer.
  2. Avoiding consent from institutional caregivers
  3. Using a larger sample to increase statistical power
  4. Publishing results before peer review

Explanation

Vulnerable populations such as institutionalized infants require special protections, including minimizing risk and ensuring that research is justified by potential benefits. Statistical power and publication speed are not substitutes for participant protection.

Question 15Ethical issues

A developmental lab keeps a database of families who have participated in past studies. Which practice best supports ethical recruitment for future studies?

  1. Adding new families from public directories without consent
  2. Calling families repeatedly until they agree
  3. Sharing the list with any interested company
  4. Contacting families only if they agreed to be recontacted Correct answer.

Explanation

Recruitment from a participant registry should honor the terms under which families agreed to be contacted. Sharing lists, adding people without consent, or pressuring families violates privacy and voluntariness.

Question 16Ethical issues

A researcher publishes a case study describing a unique developmental disorder in a small town. Which step best reduces the risk of deductive disclosure?

  1. Reporting the family's exact address
  2. Changing or masking details that could identify the child Correct answer.
  3. Including the child's photograph for clinical value
  4. Naming the town to aid future researchers

Explanation

Deductive disclosure occurs when unique details allow readers to identify a participant even without a name. Masking nonessential identifying details protects confidentiality while preserving scientific value.

Question 17Ethical issues

A study finds that a widely used parenting intervention harms children's language outcomes. The funder asks the researcher to delay publication. What is the most ethically sound course?

  1. Withdraw the study and destroy the data
  2. Alter the results to show no effect
  3. Delay publication indefinitely to satisfy the funder
  4. Report the findings accurately and disclose the funder's request Correct answer.

Explanation

Researchers have an obligation to report findings honestly, including unfavorable results, and to disclose attempts to suppress them. Suppressing or altering findings harms science and the public who rely on it.

Question 18Ethical issues

A researcher wants to test a new attachment-based intervention with children in foster care. Which combination of safeguards best meets ethical standards for this population?

  1. Only the researcher's clinical judgment
  2. A waiver of all consent because the children are in state care
  3. IRB review, independent safety monitoring, guardian consent with child assent, and a plan for referral if distress occurs Correct answer.
  4. Payment large enough to guarantee enrollment

Explanation

Research with foster children, a highly vulnerable group, requires IRB oversight, safety monitoring, layered consent and assent, and clear referral pathways. Clinical judgment alone, blanket waivers, or large payments do not provide adequate protection.

Question 19Ethical issues

An IRB is reviewing a study that will randomly assign some children to a no-treatment control group for a condition with a known effective treatment. Which consideration is most relevant to the ethical judgment?

  1. Whether the study can be completed quickly
  2. Whether the treatment is popular with parents
  3. Whether withholding treatment exposes the control group to more than minimal risk given available alternatives Correct answer.
  4. Whether the control group is cheaper to run

Explanation

The ethical acceptability of a no-treatment control depends on the risks of withholding an effective treatment and whether acceptable alternatives exist. Cost, popularity, or speed do not determine whether withholding treatment is justified.

Question 20Ethical issues

A researcher studying moral development in adolescents uses a vignette that depicts a violent scenario. Participants later report distress. Which action best reflects the ethical principle of debriefing?

  1. Collect follow-up data without addressing the distress
  2. Explain the purpose of the vignette and provide resources to address any distress Correct answer.
  3. Refuse to discuss the study to protect the design
  4. Tell participants the vignette was real to preserve realism

Explanation

Debriefing involves explaining the study's purpose and addressing any lingering distress, including providing resources when needed. Maintaining deception after the study or ignoring distress fails the debriefing obligation.

Question 21Biological development

Which sequence correctly describes the cephalocaudal pattern of physical growth in infancy?

  1. Head and upper body develop before the lower body and legs Correct answer.
  2. Legs and feet develop before the head and trunk
  3. Growth proceeds equally in all body regions at the same rate
  4. Fingers and toes develop before the arms and legs

Explanation

The cephalocaudal principle states that development proceeds from head to tail, so the brain and head grow most rapidly early in infancy, followed by the trunk and then the limbs. This explains why infants gain control of the head and neck before they can control their legs for walking.

Question 22Biological development

The proximodistal principle of motor development predicts that an infant will typically master which skill first?

  1. Picking up a small pellet with the thumb and index finger
  2. Rotating the wrist to turn a doorknob
  3. Grasping a rattle with a coordinated whole-hand grip
  4. Moving the whole arm toward an object Correct answer.

Explanation

Proximodistal development proceeds from the trunk outward, so large proximal movements of the shoulder and upper arm appear before fine distal control of the fingers and wrist. Reaching with the whole arm therefore precedes pincer grasp and other refined hand movements.

Question 23Biological development

Which statement best characterizes the normal timing of puberty onset in girls compared with boys?

  1. Boys begin puberty earlier, but girls complete it sooner
  2. Boys generally begin puberty about two years earlier than girls
  3. Girls generally begin puberty about two years earlier than boys Correct answer.
  4. Girls and boys begin puberty at essentially the same average age

Explanation

On average, girls enter puberty around age 10 to 11 and boys around age 12 to 13, so girls typically begin roughly two years earlier. This sex difference in timing is one of the most reliable findings in the developmental literature on adolescence.

Question 24Biological development

A 14-year-old boy who matured early is most likely to show which pattern of psychosocial adjustment compared with later-maturing peers?

  1. Persistent deficits in self-esteem that worsen throughout adolescence
  2. Some short-term advantages in status and self-confidence, with risks if he affiliates with older peers Correct answer.
  3. No measurable difference in peer relations or self-perception
  4. Delayed identity formation relative to later-maturing boys

Explanation

Early-maturing boys often gain temporary social advantages such as greater athletic status and confidence, but they also face elevated risk when they join older peer groups that expose them to adult behaviors prematurely. The effects are therefore mixed and context-dependent rather than uniformly positive or negative.

Question 25Biological development

Which structure is the primary site of synaptic pruning during childhood and adolescence?

  1. The umbilical cord, where connections are eliminated after birth
  2. The placenta, where connections are eliminated during gestation
  3. The cerebral cortex, where unused synaptic connections are eliminated Correct answer.
  4. The amniotic sac, where connections are eliminated before birth

Explanation

Synaptic pruning occurs mainly in the cerebral cortex, where connections that are rarely used are eliminated while frequently used ones are strengthened. This process increases the efficiency of neural networks and continues into adolescence and early adulthood.

Question 26Biological development

Myelination of the prefrontal cortex continues well into which period of development?

  1. Early childhood, ending by about age five
  2. The first trimester of prenatal development
  3. The preschool years, ending by about age three
  4. Late adolescence and early adulthood Correct answer.

Explanation

Myelination of prefrontal regions that support planning and impulse control continues into the twenties, which helps explain the maturational gap between adolescent emotional reactivity and adult self-regulation. Earlier myelination in sensory and motor areas accounts for the earlier emergence of those functions.

Question 27Biological development

The neural tube, which eventually gives rise to the brain and spinal cord, forms during which prenatal period?

  1. The fetal period, after the eighth week
  2. The germinal period, in the first two weeks after conception Correct answer.
  3. The third trimester, when organs mature
  4. The perinatal period, just before and after birth

Explanation

Neural tube formation begins during the germinal period and closes early in the embryonic period, roughly within the first month after conception. Because this occurs so early, folic acid deficiency and other insults during this window can produce serious neural tube defects.

Question 28Biological development

A pregnant woman is most vulnerable to teratogens that affect the structural formation of major organs during which period?

  1. The germinal period, before implantation
  2. The postnatal period, after birth
  3. The embryonic period, when major organ systems are forming Correct answer.
  4. The fetal period, after organ systems are largely formed

Explanation

The embryonic period, roughly weeks three through eight, is when the major organ systems are laid down, so teratogens during this window can cause structural malformations. Later exposure during the fetal period tends to affect growth and function rather than basic organ architecture.

Question 29Biological development

Fetal alcohol exposure is most strongly associated with which pattern of outcomes?

  1. Facial anomalies, growth restriction, and cognitive deficits Correct answer.
  2. Delayed puberty with otherwise typical development
  3. Enhanced language development and accelerated motor milestones
  4. Isolated hearing loss with no cognitive effects

Explanation

Alcohol is a teratogen that can produce fetal alcohol spectrum disorders, characterized by distinctive facial features, prenatal and postnatal growth restriction, and lasting cognitive and behavioral deficits. There is no known safe amount of alcohol during pregnancy.

Question 30Biological development

Which statement about the Apgar scale is accurate?

  1. It records the mother's blood pressure and recovery after delivery
  2. It assesses heart rate, breathing, muscle tone, reflexes, and color shortly after birth Correct answer.
  3. It measures the newborn's intelligence and predicts later academic achievement
  4. It is administered only to preterm infants in the neonatal intensive care unit

Explanation

The Apgar scale is a quick screening tool administered at one and five minutes after birth that rates five signs of newborn condition: heart rate, respiratory effort, muscle tone, reflex irritability, and skin color. Scores indicate whether immediate medical attention is needed.

Question 31Biological development

According to research on newborn sensory capacities, which sense is generally the least developed at birth?

  1. Hearing, which is essentially absent at birth
  2. Touch, which is nearly fully functional
  3. Vision, which is blurry and limited in acuity Correct answer.
  4. Smell, which is highly responsive to familiar odors

Explanation

Vision is the least mature sense at birth, with poor acuity and limited color discrimination that improve rapidly over the first months. Hearing, touch, and smell are comparatively well developed in the newborn, which supports early responsiveness to caregivers.

Question 32Biological development

What does the rooting reflex accomplish in a newborn?

  1. It causes the infant to grasp an object placed in the palm
  2. It turns the head toward a touch on the cheek, helping the infant locate a nipple for feeding Correct answer.
  3. It makes the infant fan the toes when the sole is stroked
  4. It produces a startle response to a sudden loud noise

Explanation

The rooting reflex is elicited by stroking the infant's cheek, causing the head to turn toward the stimulus and the mouth to open in search of a nipple. It serves an adaptive feeding function and typically fades over the first months of life.

Question 33Biological development

The persistence of which reflex beyond the expected age would most warrant developmental evaluation?

  1. The sucking reflex, if it is present during feeding in the first month
  2. The Moro reflex, if it occurs when the infant is startled in the first month
  3. The rooting reflex, if it appears in the first week of life
  4. The Babinski reflex, if the toes continue to fan after about two years Correct answer.

Explanation

Many early reflexes disappear on a predictable schedule as cortical control matures, and their persistence can signal neurological problems. The Babinski response typically gives way to a downward toe response by around age one to two, so continued fanning beyond that window merits assessment.

Question 34Biological development

The Moro reflex is typically elicited by which event?

  1. A gentle stroke on the sole of the foot
  2. A sudden loud noise or a sensation of loss of support Correct answer.
  3. A touch on the palm of the hand
  4. A stroke on the cheek near the mouth

Explanation

The Moro reflex is a startle response in which the infant extends the arms and then pulls them inward, usually triggered by a loud sound or a sudden change in support. It is a normal sign of neurological responsiveness in early infancy.

Question 35Biological development

Which statement about brain lateralization is best supported by developmental research?

  1. The two hemispheres become increasingly specialized for different functions over development Correct answer.
  2. Lateralization is complete at birth and never changes
  3. Lateralization refers to differences in physical size between the hemispheres
  4. Both hemispheres are functionally identical throughout the lifespan

Explanation

Lateralization is the process by which the hemispheres take on specialized roles, such as language functions typically relying more on the left hemisphere. This specialization emerges and strengthens over development rather than being fixed at birth.

Question 36Biological development

Which finding best illustrates experience-dependent brain development?

  1. Children who practice a musical instrument show changes in motor and auditory cortical areas Correct answer.
  2. All infants acquire language on the same timetable regardless of exposure
  3. All infants develop the ability to see contrast edges regardless of visual input
  4. All infants develop depth perception at the same age regardless of experience

Explanation

Experience-dependent development refers to neural changes shaped by specific individual experiences, such as musical training altering motor and auditory circuits. This contrasts with experience-expectant development, which relies on experiences nearly all infants encounter.

Question 37Biological development

Which statement about the secular trend in physical growth is accurate?

  1. Average adult height has steadily decreased worldwide over the past century
  2. Secular trends show no relationship to nutrition or health conditions
  3. Puberty now begins later than it did a century ago in most developed nations
  4. Average height and earlier puberty onset have increased in many populations over recent generations Correct answer.

Explanation

The secular trend refers to generational changes in growth, typically increases in average height and earlier pubertal timing, attributed largely to improved nutrition and health. These trends can slow or reverse when living conditions worsen.

Question 38Biological development

Which pattern of growth is characteristic of infancy compared with later childhood?

  1. Very rapid growth in the first year that gradually slows thereafter Correct answer.
  2. Steady growth that accelerates sharply in middle childhood
  3. Growth that is essentially complete by the end of the first year
  4. Growth that occurs only in the legs during the first year

Explanation

Infants grow more rapidly in the first year than at any other postnatal period, roughly tripling birth weight, and the rate then decelerates through childhood. A second rapid growth spurt occurs at puberty.

Question 39Biological development

A researcher finds that infants who were born preterm but received intensive early stimulation show cognitive scores similar to full-term peers by age three. Which concept does this best illustrate?

  1. The absence of sensitive periods in early cognitive development
  2. The irreversibility of prenatal damage to the central nervous system
  3. Neural plasticity allowing the developing brain to compensate for early adversity Correct answer.
  4. The dominance of genetic factors over environmental input in early development

Explanation

Plasticity is the brain's capacity to reorganize and compensate in response to experience, which can allow preterm infants given enriched stimulation to catch up cognitively. This demonstrates that early outcomes are not fixed and can be modified by environmental input.

Question 40Biological development

Which hormone is most directly responsible for the pubertal growth spurt and the development of secondary sex characteristics in both sexes?

  1. Melatonin, which regulates sleep-wake cycles
  2. Thyroxine, which regulates metabolic rate from infancy
  3. Insulin, which regulates blood glucose
  4. Sex hormones such as testosterone and estrogen released at puberty Correct answer.

Explanation

Rising levels of sex hormones, including testosterone and estrogen, drive the adolescent growth spurt and secondary sex characteristics. These hormones increase in both sexes at puberty, though in different proportions.

Question 41Perception

A researcher shows a newborn the same visual stimulus repeatedly until looking time declines, then presents a novel stimulus. The newborn's renewed looking is interpreted as evidence that the infant discriminated the two stimuli. Which method is being used?

  1. Habituation–dishabituation paradigm Correct answer.
  2. Preferential looking paradigm
  3. Contingency reinforcement procedure
  4. Visual cliff procedure

Explanation

In habituation–dishabituation, response decline to a repeated stimulus indexes encoding, and recovery of responding to a new stimulus shows discrimination. Preferential looking instead compares spontaneous attention to two simultaneously presented stimuli. The visual cliff tests depth perception, and contingency procedures test learning of response–outcome relations.

Question 42Perception

Infants as young as a few days old reliably turn their eyes and head toward a sound presented to one side. This behavior is best described as which phenomenon?

  1. Intersensory redundancy
  2. Auditory looming
  3. Auditory localization Correct answer.
  4. Phonetic categorization

Explanation

Orienting the eyes and head toward a lateral sound source is auditory localization, an early-developing spatial hearing skill. Looming refers to perceived approach of a sound, phonetic categorization concerns speech sound classes, and intersensory redundancy concerns synchronized multimodal information.

Question 43Perception

In a preferential looking study, a 2-month-old is shown a patterned checkerboard beside a plain gray square. The infant looks longer at the checkerboard. What does this result most directly indicate?

  1. The infant can perceive the checkerboard as a three-dimensional object
  2. The infant has already achieved shape constancy
  3. The infant discriminates the two panels and prefers the patterned one Correct answer.
  4. The infant has learned the checkerboard through prior reinforcement

Explanation

A preferential looking result requires that the infant detect a difference between the two displays and that the difference drive attention. Longer looking at the pattern therefore indicates discrimination plus preference. It does not by itself show shape constancy, depth perception, or reinforcement learning.

Question 44Perception

A newborn is presented with a visual target and a competing sound is played. Compared with older infants, newborns are most likely to show which pattern?

  1. Complete failure to detect the visual target
  2. Preference for the sound over the visual target regardless of conditions
  3. Immediate and precise visual fixation on the target
  4. Slower and less reliable orienting to the visual target Correct answer.

Explanation

Newborn orienting is present but sluggish and easily disrupted, and competing stimulation interferes with it. Visual attention becomes faster and more selective over the first months. Complete failure to detect the target or a fixed modality preference is not the typical newborn pattern.

Question 45Perception

An infant looks longer at a display containing four dots than at one containing two dots, with total display area held constant. This outcome is most consistent with which conclusion?

  1. The infant is using binocular disparity to judge the displays
  2. The infant has mastered object permanence
  3. The infant prefers displays with larger individual elements
  4. The infant is sensitive to numerosity differences Correct answer.

Explanation

When overall area and element size are controlled, longer looking at the larger set points to sensitivity to number. Controls for continuous variables such as area are exactly what allow this inference. Binocular disparity and object permanence are unrelated to the manipulation.

Question 46Perception

A caregiver notices that a 5-month-old reaches accurately toward a brightly colored toy but reaches less accurately toward a pale toy of the same size and distance. Which perceptual factor best explains the difference?

  1. Auditory localization
  2. Contrast sensitivity Correct answer.
  3. Motion parallax
  4. Size constancy

Explanation

Contrast sensitivity governs how well a target's edges are detected against its background, and infants need higher contrast than adults to see a target clearly. A pale toy has lower contrast, so guidance of reaching is poorer. Size constancy, motion parallax, and auditory localization do not depend on the target's luminance contrast.

Question 47Perception

An infant is placed on the shallow side of a visual cliff apparatus and crosses readily, but refuses to cross to the mother when placed on the deep side. Which interpretation is best supported?

  1. The infant cannot yet discriminate the two sides of the apparatus
  2. The infant has developed a fear of the mother's face
  3. The infant is relying on auditory cues to judge the drop
  4. The infant detects the drop-off and shows wariness of heights Correct answer.

Explanation

Refusal to cross the deep side while crossing the shallow side indicates that the infant perceives the drop-off and acts warily. The apparatus manipulates visual depth information, not the caregiver's identity. Discrimination of the sides is precisely what the differential behavior demonstrates.

Question 48Perception

A 3-month-old and a 9-month-old are tested for sensitivity to binocular disparity. What is the most accurate statement about the expected developmental change?

  1. Sensitivity to disparity emerges in the early months and improves markedly by around 4 to 5 months Correct answer.
  2. Sensitivity to disparity does not appear until after the first birthday
  3. Sensitivity to disparity is unrelated to the onset of stereopsis
  4. Sensitivity to disparity is present at birth and then declines

Explanation

Binocular disparity sensitivity is absent or weak in the newborn period and emerges over the early months, with stereopsis becoming robust around 4 to 5 months. This onset is tied to the development of cortical binocular mechanisms. Claims of decline, of appearance only after one year, or of independence from stereopsis are inaccurate.

Question 49Perception

An infant watches a rod move behind a block that hides its middle section, and then looks longer when the rod is later shown as two separate pieces. What does this pattern suggest about the infant's perception?

  1. The infant perceived the partly occluded rod as a single connected object Correct answer.
  2. The infant failed to detect the rod at all
  3. The infant perceived the two visible segments as unrelated objects from the start
  4. The infant was using only auditory information about the rod

Explanation

Longer looking at the broken rod means the display violated an expectation formed from the earlier occlusion event. That expectation implies the infant had perceived the moving segments as one connected object. Failure to detect the rod or initial perception of two unrelated pieces would not produce this surprise.

Question 50Perception

An infant is habituated to a face presented at one distance and then tested with the same face at a greater distance. Looking time remains low. Which ability does this outcome illustrate?

  1. Color constancy
  2. Size constancy Correct answer.
  3. Perceptual narrowing
  4. Shape constancy

Explanation

Unchanged responding across a change in viewing distance indicates that the infant perceived the face's actual size rather than its retinal image size, which is size constancy. Shape constancy concerns form across orientation changes, color constancy concerns hue under illumination change, and perceptual narrowing concerns attunement to familiar categories.